Observatory,' by Professor William H. Pickering.
The first expedition was to the summit of Pikes Peak, in 1887, where at an altitude of 14,200 feet, there was a stone hut erected, by the U. S. Signal Service. Observations were made for a month, and it was concluded that altitude was not as important a factor in "the seeing" as dryness. In the following year an expedition went to California and erected a pier and a building with a revolving drum on Mt. Wilson at an altitude of 5,700 feet. This observatory was occupied for more than a year, and the definition was found to be good. There was, however, some question as to the title of the land and there were advantages in selecting a location for the observation of southern stars. As Mr. Bailey had reported favorably on the Peruvian climate, the next expedition was sent there, and the Mt. Wilson site was abandoned. It has since been occupied by the buildings and fine instruments of the Solar Observatory of the Carnegie Institution.